This is Part I of a three-part series by Freedom of the Press Foundation on the Espionage Act of 1917 on its 100th anniversary. Read Part II and Part III here.

“I very much fear that with the best of intention we may place upon the statute books something that will rise to plague us in the immediate future,” the senator warned.

It was April 1917, and Senator Charles Thomas of Colorado had serious concerns about the bill before the U.S. Senate. Following extensive debate and a few modifications, though, the bill passed both the Senate and the House of Representatives.

One hundred years ago today, on June 15, 1917, President Woodrow Wilson signed the bill into law. Officially titled "An act to punish acts of interference with the foreign relations, the neutrality and the foreign commerce of the United States, to punish espionage, and better to enforce the criminal laws of the United States, and for other purposes," the law is more commonly known as the Espionage Act of 1917.

Senator Thomas’ warning about the Espionage Act would prove prescient in the century after it became law, as its vague language about foreign espionage was re-interpreted as a broad prohibition against the activities of anti-war activists, whistleblowers and journalists.

The Espionage Act was originally one of a series of bills that Congress passed in 1917 as the nation prepared to enter World War I, including bills establishing a draft and regulating the domestic economy. The law was ostensibly an attempt to stiffen penalties against espionage activities, including the collection and communication of sensitive national security information, that would benefit Germany and other nations waging war against the U.S.

I very much fear that with the best of intention we may place upon the statute books something that will rise to plague us in the immediate future

In the century since the act went into effect, it’s been used against much more than just foreign spies. Socialists, anti-war activists, whistleblowers and journalists have all found themselves targets of the Espionage Act. The law — which remains on the books to this day, as Title 18, Part 1, Chapter 37 of the U.S. Code — has grown into an American version of the U.K.’s “Official Secrets Act,” which outlaws the disclosure of any “information, documents or other articles relating to security or intelligence.”

How did the Espionage Act, originally intended to prevent German espionage during WWI, grow into a broad anti-disclosure law? It’s mostly thanks to a few amendments and a lot of creative re-interpretation by federal prosecutors and judges.

From the very start, the Espionage Act had a First Amendment problem.

Members of Congress, even in 1917, knew such a law could have serious implications for the freedom of the press, and many were divided on whether the government had the authority to restrict the press from publishing certain information—even during wartime.

An early draft of the Espionage Act included a section, at President Wilson’s behest, that would have given the president the power to issue regulations about what the press was and was not allowed to report. That provision aroused great debate in the Senate.

Senator Thomas of Colorado offered a strong defense of press freedom.

“Of all times in time of war the press should be free,” he said. “That of all occasions in human affairs calls for a press vigilant and bold, independent and uncensored. Better to lose a battle than to lose the vast advantage of a free press.”

“I am a thorough believer in the freedom of the press,” he said later during the debate. “I know that freedom has been abused. It must be abused in countries like this.”

Senator Knute Nelson of Minnesota, a Civil War veteran, took a different view of the press, recalling how newspapers had published daily troop movements during the Civil War.

“I remember well how the movements of our Army were constantly hampered because of the daily publicity that was given to all our movements and all our preparations by the press of the country,” he said. “They had reporters from most of the leading papers of the country with every army in the field and they would report every movement.”

He also compared journalists to mustard gas.

“[The war] has compelled the soldiers of the allies to protect themselves with masks against poisonous gases,” he said. “I think we owe it as a duty to protect our own men, our soldiers and sailors, in like manner against the gases of these newsmongers, these publishers here. We had better pass legislation that will operate like the gas masks in Europe to protect our soldiers and sailors against the insidious attacks of these men.”

Other senators tried to figure out where exactly the line could be drawn and how to ensure that the final version of the bill was narrow enough to criminalize spying without criminalizing journalism. This involved a lot of hypotheticals.

“Suppose a newspaper correspondent were to go into the office of the Secretary of War and talk to him about the number of troops that were in a certain division or under a certain command, or about the movement of those troops, whether that information is ever used or not, whether it is ever published or not, under the terms of this provision that in and of itself makes him guilty of a violation of the statute,” Senator James Watson of Indiana said.

“There ought not to be, it seems to me, a crime made of something collected in good faith, or some information solicited for a lawful purpose about our own country and our own conditions simply because it might be made useful to the enemy if somebody conveyed it to them,” Senator Thomas Sterling of South Dakota said.

“If a man publishes in a paper plans of our military authorities which do become of use to the enemy, although the publisher did not intend that they should, is it within the power of Congress to pass any law to punish him for publishing such things, although he did not intend to furnish aid and comfort to the enemy?” Senator Frank Brandegee of Connecticut asked.

There were endless discussions about whether the proposed statute should include words like “intent” and whether to replace the phrase “might be useful to the enemy” with “calculated to be useful to the enemy.” There was also a debate over whether Congress was restrained by the First Amendment during wartime. Senator Thomas Walsh of Montana argued that Congress’ authority to wage war included the ability to pass legislation that curtailed First Amendment rights.

“Seeing that it is a war measure, applicable only in time of war, the committee believed that we could afford to subject the innocent citizen to whatever discomfort might come to him by reason of this act, rather than to allow promiscuous publications to be made that might be invaluable to the enemy,” he said.

But Senator Thomas of Colorado warned that the law, though passed during wartime, could quickly outgrow its original purpose.

“Yet we are going ahead with this as a war measure, although when enacted it will be permanent in its operation,” he said.

In the end, the provision allowing the president to exercise overt censorship over the press was removed before the law was passed. The final version of the bill included prohibitions on the collection, retention, communication and publication of “information respecting the national defense with intent or reason to believe that the information is to be used to the injury of the United States, or to the advantage of any foreign nation.”

Congress likely thought that it had passed a relatively narrow law targeting foreign spies, without any provisions regarding censorship of the press.

A 1973 Columbia Law Review article summed up the legislative history of the Espionage Act: “It was enacted after a series of legislative debates, amendments and conferences that may fairly be read as excluding criminal sanctions for well-meaning publication of information no matter what damage to the national security might ensue and regardless of whether the publisher knew its publication would be damaging.”

If a man publishes in a paper plans of our military authorities which do become of use to the enemy, is it within the power of Congress to pass any law to punish him for publishing such things, although he did not intend to furnish aid and comfort to the enemy?

Unfortunately, the sections of the law pertaining to foreign espionage were worded so vaguely that federal prosecutors and courts began in the latter half of the 20th century to use the law against both journalists and their sources.

The first victims of the Espionage Act, however, were members of the Socialist Party, thanks to a package of amendments passed in 1918 known as the “Sedition Act.” These amendments outlawed “disloyal, profane, scurrilous, or abusive language” that aimed to “incite, provoke or encourage resistance to the United States, or to promote the cause of its enemies.” It was mainly targeted at socialist activists who opposed U.S. involvement in WWI, and criticized the mandatory military draft. Socialist Party presidential candidate Eugene Debs, Socialist Party general secretary Charles Schenk, and anti-war newspaper publisher Jacob Frohwerk were three of the many socialists charged and convicted under the new provisions of the Espionage Act.

In early 1919, the Supreme Court upheld the convictions of Schenk, Frohwerk and Debs. In a shameful series of unanimous opinions written by Justice Oliver Wendell Holmes, Jr., the Court ruled that the First Amendment did not prevent Congress from prohibiting speech that could undermine the war effort during wartime.

Holmes infamously declared that just as the First Amendment would not protect “falsely shouting ‘fire’ in a crowded theatre,” so it did not protect Schenk, who was accused of publishing leaflets critical of the draft. Frohwerk was accused of publishing anti-war articles; Holmes said that amounted to a “wilful obstruction” of the U.S. military’s recruitment efforts. Debs was accused of giving an anti-war speech that praised draft dodgers; Holmes said that had the “intention and effect of obstructing the draft and recruitment for the war.”

The Sedition Act was repealed in 1920, and President Warren Harding commuted Debs’ sentence the following year. The Supreme Court decisions in Schenk, Frohwerk and Debs were never explicitly overturned, but later Court decisions established much stronger free speech protections and thankfully those decisions are generally considered bad law today.

Then, during World War II, there were aborted attempts to use the Espionage Act directly against the press.

In 1942, the Chicago Tribune reported that the U.S. Navy had advance knowledge of Japan’s naval strategy in the Battle of Midway. The article allegedly implied that the U.S. Navy had found a way to decrypt the Japanese military’s encoded messages — a fact which was not yet public knowledge. President Franklin Roosevelt, angry that the Tribune article would prompt the Japanese to change their secret code, asked the Department of Justice to look into charging the Tribune reporter under the Espionage Act. A grand jury was empaneled in Chicago, but the members of the grand jury declined to issue an indictment against the reporters.

In 1945, the FBI raided the offices of the pro-Communist foreign affairs journal Amerasia, which had obtained hundreds of U.S. intelligence and State Department documents marked “secret” and “top secret” and published articles based on them. The journal’s editors, and its sources in the federal government, were arrested on charges of violating the Espionage Act. But a grand jury — finding no evidence that the defendants had passed classified information to foreign governments — declined to issue any indictments under the Espionage Act, instead charging some of the Amerasia staffers with the lesser offense of theft of government property.

The failure to prosecute Amerasia editors for for espionage enraged conservative politicians, including Sen. Joseph McCarthy, who exploited the case to argue that the federal government was soft on Communism because it had been infiltrated by secret Communists.

In the ensuing anti-Communist hysteria, Congress passed a number of laws focused on domestic security and the suppression of left-wing political ideology. Among these laws were bills that amended the Espionage Act, adding section 798 and sub-sections 793(e) and (g).

Sub-section 793(e) applies the Espionage Act to people who disclose national security information that they were never authorized to have in the first place, while 793(g) makes it a crime to “conspire to violate” the Espionage Act, even if no national security information is actually disclosed. In other words, the Espionage Act doesn’t just apply to government employees who violate their security clearances by providing sensitive national security information to foreign spies; it applies to any person who learns of such information and then communicates it to any other person.

Section 798 expands the scope of the Espionage Act to cover all classified information related to communications intelligence (e.g. wiretaps), including all classified information “obtained by the processes of communication intelligence from the communications of any foreign government.” Under 798, it’s not just illegal to disclose the methods that the U.S. government uses to spy on foreign governments; it’s also illegal to disclose any classified information that the U.S. government learns as a result of that spying.

These amendments transformed the Espionage Act, which had started as a wartime anti-spying statute, into a broad statute that outlawed the possession and communication of entire classes of information.

Nobody other than a spy, saboteur, or other person who would weaken the internal security of the Nation need have any fear of prosecution

If we were to take the Espionage Act at its face value, it is likely illegal for you to talk to anyone without a security clearance about any information marked “classified” that was obtained through signals intelligence. It does not matter whether you had a top-secret security clearance or just found a classified document on the sidewalk, nor does it matter why you decided to communicate the information or whether the disclosure of the information was actually harmful. It is illegal merely to know and communicate certain information.

It’s not clear that this was actually what Congress intended when it passed these absurdly broad amendments to the Espionage Act.

In 1949, as Congress was debating proposed amendments to the Espionage Act, Senator Harley Kilgore of West Virginia wrote a letter to Senator Pat McCarran on Nevada, the sponsor of the legislation, warning that the amendments “might make practically every newspaper in the United States and all the publishers, editors, and reporters into criminals without their doing any wrongful act.” McCarran asked Attorney General Tom Clark to respond to Kilgore, and Clark tried to reassure the senator that journalists would have nothing to fear from the Espionage Act.

“The history and application of the existing espionage statutes which this bill would amend only in part,” the attorney general wrote, “and the language, history, hearings and report of the committee relative to this bill, together with the integrity of the three branches of the Government which enact, enforce, and apply the law, would indicate that nobody other than a spy, saboteur, or other person who would weaken the internal security of the Nation need have any fear of prosecution under either existing law or the provisions of this bill.”

Two decades later, the federal government tried to use the Espionage Act against newspapers.